Compressor-controlling mechanism



Nov. 6 1923. 1,473,598

' L. J. CLAPP COMPRESSOR CONTROLLING MECHANISM Filed 001:. 7, 1918 2Sheets-Sheet 1 lnveni'o 7?. Lewis J fiiagbjb.

Nov. 6, 1923.

i L. J. CLAPP COMPRESSOR CONTROLLING MECHANISM Filed Oct. 7, 1918 2Sheets-Sheet 2 Fig; A

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3/ J4 J5 AZ 1111:2111-2011- Lewis Q9 trou h a- Patented Nov. 6, i923.

fiTATES Pdlfi LEWIS JOSEPH CLAPP, OF CLA BEMONT, NEW HAMPSHIRE, ASSIGNORTO SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS.

COMPRESSOR-CONTROLLING MECHANISM.

Application filed October 7, 1918. Serial No. 257,135.

To allwlwmitma concern:

Be it known t at I, LEWIS J. CLAPP, a

citizen of the United States, residing at' using electric motors fordriving compres-- sors, if the motor is started witha full load on thecompressor, several times the normal amount of current is requiredduring the starting period in order to et the motorup to speed, or themotor W1 1 not have sufficient power to start the compressor under thisload. It is one object of this invention to devise means for unloadingthe compressor by terminal pressure and for unloading the compressorduring the starting period of the motor, the unloading controllingmechanism operating to stop the motor when the compressor has beenunloaded for a predetermined length of time.

My invention will be best understood by reference to the illustrativeembodiment thereof shown in the accompanying drawings, and will be moreparticularly pointed out in the appended claims.

In the drawings,-

Fig. 1 is a side elevation of a compressor system having my improvedcontrolling mechanism attached thereto.

Fig. 2 is a longitudinal section of the controlling means, parts thereofbeing shown in elevation.

Fig. 3 is a sectional view of an improved Judson valve.

Referring to the drawings. I have there shown, for the purpose ofillustrating the principal features of the invention, a compressorsystem which includes a compressor cylinder 1, a motor 2 which operatesa piston in the cylinder 1, through the usual piston rod, crosshead,pitman, and crank shaft (not herein necessary to show), the lattercarrying a flywheel 3, and being driven by the motor through suitablegearing, not shown, the Whole being mounted on a single base 4. Thecylinder 1 is provided with inlet valves 5, a common type of unloadingmechanism 6, and exhaust valves 7 through which the air is forced toa'pipe 8 which conducts the compressed fluid to a receiver 9. A smallpipe 10 is interconnected between the receiver 9 and a Judson valve 11,the latter being mounted on my improved motor and unloader controllingvalve 12.

,The Judson valve 11 is, in general, of usual construction, as is shownin Fig. 3, and comprises a diaphragm 13, a compression spring 14, aregulating cap 15, and a plunger 16 adapted to be moved by the diaphragmagainst a disk 17. Springs 18 and 19 tend to move the plunger 16 anddiskl7 upward against the action of the spring 14.

en the receiver pressure overbalances the spring 14, the plunger 16 israised-out of contact with the disk 17, and the air under pressurepasses through. the plunger and perforations in the disk to the valve12. As the receiver pressure falls, the plunger 16 again seats on thedisk 17, and the air The Valve 12, which also constitutes a servo-motoras will hereinafter appear, (-see Fig. 2) is composed of a centrallydisposed cylinder 24 around which is an annular chamber 25 communicatingwith the Judson valve 11 and also communicating with the cylinder 24through openings provided between the end of the cylinder wall and thecylinder head 26. A piston 27 slides in the cylinder 24 and isnormally-held to one end thereof against bosses 28 formed on the head26, by a spring 29. Mounted in the head of the piston is a check valve30, of common construction, which permits a flow of air under pressurefrom the annular chamber 25 to an annular recess 31 formed on thepiston, the annular recess 31 always being in communication with a pipe32 which conducts the fluid under pressure to the unloading means 6, andbeing in communication with a small exhaust port 33 when the piston 27is seated against the bosses 28. The spring 29 bears against a head 34adjustably mounted on a sleeve 35, which also carries in adjustablerelation therewith a stem 36. Lock nuts 34, 35' are provided for holdingthese members 34, 36' in adjusted position. This stem 36' is adapted,when the piston is moved to the extreme left hand position, to contactwith a pin 36 of a floor switch '37 of ordinary construction mounted onone end of the valve 12, and here shown diagrammatically as havingcontacts 38 and a bridge 39 for connecting the contacts, the bridgebeing operated by the pin 36 in a well known manner. The contacts 38 areconnected with wires 40 which operate, through an electromagnet 41, theswitch 42 which starts and stops the driving motor 2. The cylinder 24,piston 27, and associated parts constitute a servo-motor for controllingthe switch 37. That is to say, these parts constitute an operating motorfor the switch 37.

The operation is as follows: During the normal operation of thecompressor, as the terminal pressure rises and passes a predeterminedpressure, the Judson valve will operate and permit a flow of pressurefluid through the annular chamber 25 to the cylinder 24, where it actson the piston to force it to the left against the action of the spring'29. It also forces the check valve 30 open and thus permits thecompressed air to pass into the annular recess 31 through the pi e 32 tothe unloading means to unload t e compressor. The check valve 30 isnormally held seated by a very light spring so that the compressed airis admitted to the unloading means before the piston 27 has been movedsufiiciently to the left against the relatively strong spring 29 tobring the stem 36' into contact with the pin 36'to break the contact at38 and so stop the motor. As the pressure in the receiver falls, thecheck valve 30 closes and the piston 27 moves to the right. Upon aninitial movement of the piston, the pin 36 is released, the contact ismade. and the motor is started. The movement of the piston to the rightmay be governed b regulating the escape of the pressure flui from thecylin-' der and chamber 25 through the ports 20 by means of the valvesor screws 22, so that the time interval between the closing of thecontact 38 and the connection of the ipe 32 with the exhaust port 33 maybe ma e as long or as short an interval as may be de-' sired. It will benoted that the chamber 25 constitutes a relatively large clearancevolume for the cylinder 24 and so retards the fall in pressure in thecylinder. When the pipe 32 is connected to the ort 33 through the recess31, the air which as held the intake valves unseated is exhausted to theatmosphere and the compressor is again loaded.

The tension of the spring 29 is such that the terminal pressure willmove the piston slowly to the left and, due to the regulation of thescrews 22, the piston can move but slowly to the right, the result beingthatas the terminal pressure fluctuates a trifle above and below thenormal receiver pressure, the piston will control the unloading andloading of the compressor without breakin the electrical contact to stopthe motor. l-lowever, if the terminal pressure rises above the normalpressure desired and remains above normal for any appreciable length oftime, the piston will move far enough to the left to break theelectrical contact and stop the compressor. The movement necessary tobring the stem 36' into contact with the pin 36 may be regulated by anadjustment of the stem in the head which forms one abutment for thespring 29. It is essential to a proper unloading of the compressor thatthe pipe 10 connectin the receiver and unloader controlling va ve shallbe of sufiicient size to prevent a rapid fall in pressure in the valvewhen the fluid under terminal pressure is admitted to the unloadingmechanism.

Thus it is seen that I have devised a simple, inexpensive, andadjustable means for throwing the load off from a compressor before thecompressor driving motor is stopped, for throwing the motor intooperation again before the compressor is loaded, and for regulating thetime which will elapse between the starting of the motor and the loadingof the compressor.

While I have herein shown and described for purposes of illustrationonespecific form of my invention, it is to be understood that the same hasbeen chosen for illustrative purposes only, and that extensivedeviations may be made from the disclosed form thereof without departingfrom the spirit of the invention.

, What I claim as new and desire to secure by Letters Patent is:

L In a compressor unloading and motor controlling mechanism, adapted foruse with a compressor system comprising a motor, a compressor, and anunloader therefor operative to discontinue the compressive action of thecompressor, the combination including means for automatically startingand stopping the motor, and means acting independently of said firstnamed means for operating the unloader to unload the compressor.

2. In a compressor unloading and motor controlling mechanism, adaptedfor the control of a compressor system comprising a motor, a compressorhaving unloading means of the type adapted to discontinue thecompressive action of the compressor, and a receiver receiving thedischarge from the compressor, the combination including means forcontrolling the motor governed by the discharge pressure of thecompressor, and means acting independently of the first named means foroperating the unloader to unload the compressor.

3. In a controlling mechanism for a compressor system comprising areceiver, a motor, a compressor driven by said motor and discharging tothe receiver, and an unloader for the compressor operative todiscontinue the compressive action thereof, in combination, a compressorunloader and motor controlling mechanism responsive to receiver pressureand comprising means for controlling the motor, and means actingindependently of the first mentioned means for operating the unloader tounload the compressor.

4. In a compressor system having a motor, a compressor and an unloadertherefor, the combination including a switch for controlling the motor,means for operating the switch, and means carried by said first namedmeans but acting independently thereof for operating the unloader tounload the compressor.

5. In a compressor system having a motor, a compressor and an unloadertherefor, the combination including a fixed member, means carriedthereby for controlling the motor and for controlling the unloader toload the compressor, and means acting independently of said first namedmeans for controlling the same and the unloader to unload thecompressor.

6. In a compressor system having a motor, a compressor and an unloadertherefor, the combination including a fixed member, means carriedthereby for controlling the motor and for controlling the unloader toload the compressor, and means acting independently of said motorcontrolling means but associated therewith. for permitting a flow ofpressure fluid to the unloader to unload the compressor.

7. In a compressor system having a compressor and an unloader therefor,the combination including "a fixed member, means for admitting a fluidunder terminal pressure to said member, and means associated with saidmember for permitting a flow of fluid only in a direction toward theunloader to unload the latter, said means being subjected to pressureonly after the normal terminal pressure is exceeded.

8. In a compressor system having a compressor and an unloader therefor,the combination including a fixed member, means for admitting a fluidunder terminal pressure to said member and for exhausting fluidtherefrom through a common port, and means associated with said memberfor permitting a flow of fluid only in a direction toward the unloader.

9. In a compressor system ha'vinga compressor and an unloader therefor,the combination including a fixed member, a movable member therein, forcontrollin a flow of actuating fluid from the unloa er, and meanscarried by said movable member and movable relative thereto forpermitting a flow of fluid only'in. a direction toward the unloader tounload the latter.

10.11121 compressor system having a compressor and an unloader therefor,the combination including a fixed member, means for admittingia fluidunder pressure to said member, a movable member in said fixed memberproviding a passage to and controlling a flow offluid from'the unloader,and a check valve for permitting a How of fluid only in a direction Itoward the unloader.

11. In a compressor system having a compressor and an unloader therefor,thecombination including a fixed member, means for admitting a fluidunder pressure to said member and for exhausting the fluid therefrom, amovable member in said fixed member for controlling a flow of fluid fromthe unloader, and means carried within said fixed member for permittinga flow of fluid only in a direction toward the unloader.

12. In a compressor system having a compressor and an unloader therefor,the combination includinga fixed member, means for admitting a fluidunder pressure to said member, a movable member in said fixed 11 memberfor controlling a flow of fluid from the unloader, and means carried bysaid movable-member f for permitting a flow of fluid only in a directiontoward the unloader.

13. In a compressor system having a com- 11 pressor and an unloadertherefor, the combination including a fixed member, compressor dischargepressure controlled means for admitting a fluid under pressure to saidmember and for exhausting the fluid therefrom, a movable member in saidfixed member for controlling a flow of fluid from the unloader, andmeans carried by, said movable member for permitting a flow of fluidonly in a direction toward the unloader.

14. In a compressor system having a compressor and an unloader therefor,the combination including a cylinder, a chamber thereon communicatingwith the cylinder, a port associated with said cylinder, means 1 forregulating a flow of fluid to the chamber and to the cylinder, and meansfor exhausting fluid from the unloader through said port.

15. In a compressor system having a motor, a compressor and an unloadertherefor, the combination comprising a fixed member, a movable membertherein adapted to control the motor when said movable member is in oneposition and adapted to load the compressor when in another position,and means acting independently of said movable member for controlling aflow of fluid toward said unloader.

16. In a compressor unloading mechanism, the combination including amember having an intake, an outlet, and an exhaust port, valve means forcontrolling a flow of fluid through the intake, and means separate fromsaid valve means for connecting the outlet with the exhaust port uponclosure of the intake.

17. In a compressor unloading mechanism, the combination including afixed member, an electrical control mounted there, on, inlet, outlet,and exhaust ports formed in said member, and means carried by the fixedmember for successively permitting a flow from inlet to outlet,operating the electrical control, reversing the operation of theelectrical control, and permitting a flow from outlet to exhaust.

18. In a compressor unloading, mechanism, the combination includingafixed member, an electrical control mounted thereon, a member movable insaid fixed member and having. adjustable means for engaging andpositively actuating saidelectrical control, and adjustable meansforcontrolling the movement of the movable member.

19. In a compressor, unloading mechanism, the combination including afixed member, an electrical control mounted thereon. an exhaust port inspaced relation to said electrical control, a movablemember operative onopposite movements thereof respectively to close said exhaust and toactuate said electrical control and to disengage said control and toopen said exhaust port, and means for regulating the relative times ofdisengaging of the electrical control and opening of the exhaust port. I

20. In a compressor unloading mechanism, the combination including afixed member, an electrical control mounted thereon, an exhaust port inspaced relation to said electrical control, a movable member adapted tocontact with the electrical control to operate the same and to controlsaid exhaust port, and means for regulating the relative times ofcontact with the electrical control and operation of the exhaust port.

21. In a compressor controlling mechanism, the combination comprising amovable member responsive to variations in terminal pressure, motorcircuit controlling mechanism, means carried by said movable member forengaging and moving said motor circuit controlling mechanism, and anormally open exhaust port controlled by said member, said port beingclosed during operation of the circuit controlling mechanism.

22. In a compressor controlling mechanism, the combination comprismginlet valve operating piston mechanism, a valve controlling the flow offluid thereto, a motor circuit controlling switch, and asingle memberresponsive to variations in terminal pressure for controlling the switchand the valve operating piston mechanism, said member cooperatingmechanically with said switch and constituting a supplemental valve forthe control of said valve operating piston mechanism.

23. In a control mechanism. for a compressor system including a motor, acompressor and an unloader for the compressor comprising motorcontrolling means, in combination, a servo-motor for actuating the motorcontrolling means, and means whereby a portion of said servo-motoroperates as a control member for said unloader.

24. In a control mechanism for a compressor system having a motor, acompressor and an unloader for the compressor, which unloader is fluidpressure controlled, in combination, motor controlling means, aservomotorfor actuating the same, and means whereby a portion of saidservo-motor operates as a control for the fluid pressure for saidunloader.

25. In a controlling mechanism for a compressor system comprising amotor, a compressor and an unloader therefor adapted for fluid pressurecontrol, the combination including motor controlling means, and aservo-motor for actuating the same, said servo-motor having a portionthereof constituting a valve for the control of the fluid pressure forsaid unloader.

26. In a controlling mechanism for a compressor system comprising amotor, a compressor and an unloader therefor adapted for fluid pressurecontrol, the combination including motor controlling means, and aservo-motor for actuating the same, said servo-motor being provided withvalve means controlling the fluid pressure for said unloader.

27. In a controlling mechanism for a compressor system comprising amotor, a compressor and an unloadertherefor adapted for fluid pressurecontrol, the combination including motor controlling means, and aservo-motor for actuating the same, said servo-motor having a pistoncomprising a lin valve for the control of the fluid pressure for saidunloader.

28. In a controlling mechanism for a compressor system comprising amotor, a. compressor and an unloader therefor adapted for fluid pressurecontrol, the combination including motor controlling means, a servomotorfor actuating the same, and a plurality of valve means formed on saidservomotor and cooperating in the control of the pressure fluid for saidunloader.

29. In a motor driven compressor controlling mechanism, the combinationcomprising a motor controlling mechanism, compressor unloading meanscomprising mechanism operative when actuated to control the condition ofthe compressor as to loading and unloading, and a member actuated byterminal pressure for controlling the motor controlmechanism and saidcompressor control ing mechanism, the control of one of said firstmentioned mechanisms being mechanical and that of the other beingpneumatic, 4

30. In a motor-driven compressor controlling mechanism, the combinationcomprising a motor controlling member, compressor unloading meanscomprising an actuating member, and a member" actuated by terminalpressure for controlling said motor controlling member and saidactuating member, said member actuated by terminal pressure beingprovided with means adapted to control directly one of said first.mentioned members, and with valve means operative in the control of theother thereof.

31. In a motor-driven compressor controlling mechanism, the combinationcomprising a motor controlling member, compressor unloading meanscomprising a fluid pressure actuated member, and a servo-motor aving apiston adapted to actuate said motor controlling member, and providedwith a groove cooperating in the supply and discharge of pressureflllld' to said pressure fluid actuated member, said piston beingcontrolled by terminal pressure.

32. In a motor-driven compressor controlling mechanism, the combinationcomprising a motor controlling member, compressor unloading means havingan actuating member, a servo-motor having a piston adapted to actuateone of said members directly and provided with-valve means cooperatingin the supply and discharge of pressure fluid to the other of saidmembers, and with supplemental valve means cooperating only with thesupply of pressure fluid to said member, and terminal pressurecontrolled means controllin the operation of said piston.

33. n a. compressor system, a compressor, fluid operated unloading meanstherefor operative on fluid supply thereto to unload a compressor, adriving motor for said compressor, fluid operated means operative onfluid supply thereto .to control the driving of said compressor by saidmotor, compressor discharge pressure controlled means for simultaneouslysupplying pressure to both of said means and interrupting the supply ofpressure thereto, said compressor discharge pressure controlled meanscomprising exhaust means for the fluid supplied to one of said two firstmentioned means/and separate exhaust means for the other of said twofirst mentioned means closed during interruption of the compressordrive.

34. In a compressor system, a compressor, fluid operated unloading meanstherefor, a driving motor for said compressor, a fluid operatedcontroller means for the circuit of said motor, and means forcontrolling the operation of said two first mentioned means including. apilot valve responsive to compressor discharge 1pressure, said meansproviding a substantia ly simultaneous initiation of the supply ofoperating fluid for both of said means and interrupting supply to bothand opening an exhaust for one of said means as soon as supply isinterrupted while subsequently opening an exhaust for the other.

35. In a compressor system, a compressor, fluid operated unloading meansassociated with the inlet valves thereof, a driving motor for saidcompressor, means for controlling said motor operated by fluid pressure,and a single receiver pressure responsive pilot valve for controllingthe supply of operating fluid for bothof said means, said pilot valvecontrolling the exhaust from one of said means, and the latter meansbeing constructed and arranged to control the exhaust from the other ofsaid means.

36. In a compressor controlling means, a member whose position governsthe output of the compressor, means for actuating said member to changeits position including a cylinder, a piston therein, means forcontrolling the supply and exhaust of operating fluid to said cylinder,and a chamber of material capacity constantly communicating with the endof said cvlinder to which operating fluid is admitted. I

37. In a compressor controlling means, in combination, a cylinder, apiston reciprocable therein when fluid pressure is supplied thereto, andmeans constituting a relatively large clearance volume for said cylinderfilled when said piston is moved wherebv return movement of said pistonis retarded by the necessity for the escape of the fluid pressurein saidclearance volume.

38. In a compressor system, in combination, a compressor, a compressordriving motor, and controlling means comprising a cylinder, a pistontherein, a motor controlling switch actuated by said piston adjacent thelimit of movement of the latter, and fluid operated compressor unloadingmeans supplied with pressure on initial movement 0 said piston andvented as said piston returns to its initial position.

39. In a compressor controlling mechanism, in combination, meansoperative on fluid supply thereto to unload a compressor and operativeon release of fluid so supplied to permit reloading, means forcontrolling 10 such fluid supply and exhaust including a memberreciprocable under fluid pressure, and another controlling mechanismengageable by said reciprocable member but disengaged before thecompressor is loaded.

In testimony whereof I aflix my signature.

LEWIS JOSEPH CLAPP.

